The Time Division Duplex (TDD) technique is one of the duplex techniques used in a mobile communication system, which corresponds to the Frequency Division Duplex (FDD) technique.
In a communication system of TDD-mode, the uplink and downlink communications between a base station and a mobile station use different time slots in the same frequency band. The uplink and downlink communications use the same frequency band, and have the same bandwidths by separating the receiving channel from the sending channel by the time. The resources for the uplink or downlink communication are not continuous in time domain, and the time resources are distributed to both the uplink and downlink communications.
For FDD, the uplink and downlink communications are respectively performed in two separate symmetrical frequency channels, and a guard band is used to separate the uplink and downlink channels. Frequencies in pair must be used in FDD, the uplink and the downlink are distinguished by the frequency, and the resources for the uplink or downlink communication are continuous in time domain.
However, during the implementation of the present invention, the inventor discovered that there are at least the following problems in the prior art.
In a TDD system, the uplink and downlink transmissions occupy all the bands. The interference between the uplink and the down link within the working band or at the edge of the working band can not be avoided when the TDD system is configured to work with the other mobile communication systems. If the band isolation is implemented by reserving the guide band, the spectrum resource is wasted greatly.